(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Text Book Of Mechanical Engineering"

586

Method of Mixture.

When the body and the water are in thermal  equilibrium, the

final temperature T of the mixture is taken.    Then, the heat

lost by the body divides itself between the  water and the
casing, so

Heat lost by body           = Heat gained by water & casing,

weight x sp. ht. x fall of temp.   = weights x sp. hts. x rise of temp.
ws (/ - T)               -        (wl s} -f wfy) (T - /!>,

where w wl and w^ are the weights in Ibs., and s sl and J2 the
specific heats of the body, the water, and the casing respectively :
jj being unity. The value w% s% is known as the * water equivalent'
of the vessel. The first temperature of the water is // while f is
that of the body after steaming; and the changes are shewn
graphically at A, Fig. 598. Inserting known values, that of

s may be found, the following table being obtained by this and
other methods:

SPECIFIC HEATS OF VARIOUS SUBSTANCES.

Water at 39 'i
	...   I '00
	Wrought iron
	...    ^113

Water at 212
	... 1-013
	Steel ......
	...    -116

Ice at       32
	...    -504
	Copper
	...    -095

Steam at 212*
	...    -48
	Coal ......
	...    '24

Mercury
	...    '033
	Air    ...    ...
	...    -238

Cast iron
	...    -13
	Hydrogen ...
	... 3"44